1. Field of the Invention
The present invention resides in a Lumbar Extension Machine which is a trunk extension exercise device for the human body. It should be noted that the LUMBAR EXTENSION MACHINE is a new and improved version of the VARIABLE ANGLE ROMAN CHAIR. The device is especially helpful in alleviating chronic low back pain of individuals suffering from severe disability and deconditioning syndrome.
In the past, devices for exercising individuals suffering from chronic low back pain were stationary at approximately 0.degree. and 45.degree. angles at the restrained pelvic portion of the device. These angles are very difficult for the initial use of such a device by some individuals. Through continued research by the inventors herein, it was determined that by varying the angle of the restrained pelvic portion of this invention from 0.degree. to 75.degree. from horizontal, that a severely disabled individual suffering from chronic low back pain could exercise at a more vertical angle where resistance is lower (i.e. 75.degree.) and progressively move to more difficult angles (i.e. 0.degree.) by virtue of a progressive resistance exercise program utilizing this device.
2. Description of the Prior Art
Numerous exercise devices exist for strengthening the various muscles of the human body. It should be noted, however, that exercises to strengthen a particular group of muscles have limitations because of the various muscle interactions. In particular, exercises for the muscles of the trunk are especially difficult to accomplish because of interaction of the back muscles with other quite powerful muscles, particularly those of the legs. Thus, stabilization of the pelvic region during the exercise is quite important. In particular, stabilization of the pelvis to prevent rotation of said pelvis during an exercise routine is needed to isolate the lumbar region of the trunk and provide for an acceptable exercise device.
Several devices have been proposed in the past to exercise various muscles on the human body.
For example, U.S. Pat. No. 4,564,193 to Stewart describes an adjustable exercise apparatus which consists of a frame, a base supporting said frame, a cable system, a guide rod supported on said frame and a weight lift slidable along said guide rod and attached to said cable system. Auxiliary apparatus such as a bicycle device, weight bench and trampoline are also disclosed.
U.S. Pat. No. 4,832,336 to Lahman relates to a multi-purpose exercising device which consists of an elongated frame having coplanar top and bottom surfaces and front and rear ends. A pivotally mounted support post is mounted near the rear end of the frame which provides for holding a pad positioned on top of the frame at an elevated angular position or extends from the rear end of the frame. A biceps femoris attachment is detachably mounted on the rear end of the frame. The device is particularly suitable for exercising abdominal muscles which can be converted to a biceps femoris exerciser.
U.S. Pat. No. 4,907,798 to Burchatz describes an exercise machine consisting of a vertically elongated open frame of sufficient height for an average individual to stand inside of it. The frame contains weights, a cable system attached to said weights, a single handle bar or a single foot bar and a bench having a front section joined by a lateral hinge to a rear back rest section.
U.S. Pat. No. 5,042,801 to Sterba, et al. relates to an exercise bench system having a lower bench that rests on a floor and contains a separate upper bench which can be adjusted to three separate positions; namely, (1) collapsed flat on the lower bench, (2) inclined relative to the lower bench and (3) upstanding parallel with the lower bench.
U.S. Pat. No. 5,110,121, to Foster discloses an exercise chair for the lower back. The chair contains both anterior and posterior pelvic restraints to prevent rotation of the pelvic region during an exercise routine. A variable resistance mechanism is inclined on the chair for selectively varying the forces that must be overcome during an exercise movement which consists of forcing the back of the chair rearwardly from an initially forward position.
U.S. Pat. No. 5,160,305 to Lin relates to a multi-functional gym exerciser containing an adjustable table. The apparatus contains a plurality of set holes wherein a user can attach a variety of exercise attachments. In addition, the table portion of the apparatus can be adjusted to a desired slope in order to achieve the best exercise effect.
U.S. Pat. No. 5,308,306 to Wang describes an abdomen exercising apparatus. The apparatus has a back rest supported on two curved supports at two opposite sides of a base by two cranks and two elastic elements. The elastic elements produce an upward force to help the user set up.